Voltage transformer



Nov; 28, 1950 N. E. LINDENBLAD 2,531,820

VOLTAGE TRANSFORMER Original Filed Feb. 3, 1943 LLQ PULSE SOURCE INVENTOR ATTORNEY UNITED STATES PATENT orrica VOLTAGE TRANSFORMER Nils E. Lindenblad, Port J eflei'son, N. vY., assignor to Radio Corporation of America, a corporation of Delaware Original application February 3, 1943, Serial No. 474,539. Divided and this application March 8, 1946, Serial No. 652,911

7 Claims. 1

This invention is a division of my copending application Ser. No. 474,539, filed February 3, 1943, now U. S Patent 2,412,345 granted December 10, 1946, and relates to improvements in high voltthe surrounding tube. The insulation material I may consist of high grade rubber, ceramic material or thermal setting varnish which fills the space between the primary tubular conductor I 2 and the interiorly located secondary conductor. The terminals of the secondary winding are labeled I06, I08. Each primary tubular conductor I00, IM and I02 is surrounded over its age iron core transformers, and particularly to 5 length by a multiplicity of spaced iron cores I01. a novel type of high voltage step-up or step- These iron cores are laminated affairs and may down transformer suitable for use in high freconsist of a thin ribbon of soft iron of good magquency systems operating at frequencies above netic quality which is enameled so that the adone megacycle. jacent surfaces of the ribbon are insulated from Among the objects of the present invention are: each other as they are wound or rolled up to To provide a high voltage iron core step-up or make a core. The core may, of course, be made step-down transformer of increased efficiency, up of iron washers or discs of the same material whereby losses due to eddy currents and hyswhich are insulated from each other and stack teresis effects are greatly reduced; to providea up to constitute the core. These cores, when well insulated high voltage set-up or step-down made of a ribbon as described above, are spaced transformer which is inexpensive to manufacture from one another by air gaps which enables the and simple to assemble; to provide a step-up heat to escape from the edges of the cores. These transformer especially applicable at frequencies air gaps are very small to permit as many cores above those normally considered in connection as possible to be placed around each tubular conwith iron core designs; and to provide a step-up ductor. When washers are used instead of a transformer especially suitable for passing microribbon to make up the core, there may be one second duration pulses of power to such electronic core for the entire length of each primary condevices as magnetrons, X-ray tubes, etc., and to ductor, the necessity of sectionalizing the core spark circuits. then disappearing due to the fact that the edges A description of the invention follows in con- 26 of each washer will, by contact with the air, projunction with the drawing, wherein: vide sufficient heat radiation and convection.

- Fig. 1 shows one embodiment of a transformer With a transformer having the design of Fig. 1, in accordance with my invention; and I am able to obtain iron cores of smallest possible Fig. 2 shows, schematically, how the transfordiameter, with a consequent saving of the volume mer of Fig. 1 can be used in cascade. 80 of the iron required to make the core. An in- Referring to Fig. 1 in more detail, there is spection of Fig. 1 will show that there is a volt" shown a transformer in which the primary and age transformation ratio of one-to-one between secondary windings consist of concentric tubings each individual tubular conductor I00, IM or of minimum radial dimensions permissible when I02 and the wire looped therein, but there will using the best possible insulating material. The 85 be a total over-all voltage transformation ratio arrangement of this figure achieves a considerof one-to-three between primary and secondary able reduction in the radius of the iron core. due to the fact that the voltages of the three The primary winding consists of three metallic portions of the conductor I04 within the three tubes I00, IOI and I02 connected together at their tubular conductors additively combine. If one ends so as to be electrically in parallel relation. end of the primary winding is grounded and one Leads 103 connected to the ends of one of these terminal I06 of the secondary winding is contubular conductors represent the terminals of the nected to the other end of the primary winding, it primary winding. The secondary winding conis possible to obtain an additional voltage transsists of an insulated conductor I 04 which is looped formation step-up from the output of the secondthrough the primary tubes Inn, ml and In: in m windin whi h i q l to t pr m ry v l series relation. The conductor I04 is insulated age. In doing this, however, care should be obfrom each of the tubes through which it is served in selecting the particular terminal of the looped by means of a highly efficient dielectric secondary which is to be connected to the end material I05 which separates the wire I04 from of the primary farthest removed from the grounded end, in order for the primary and secondary voltages to add. If the wrong terminal of the secondary is connected to the ungrounded end of the primary winding, the primary and secondary voltages would subtract rather than add.

i As one illustration of a practical embodiment which the transformer of Fig. 1 may take, the metallic tubes I00, l0l, I02 should be of the same length and each may be eight inches long. The voltage applied to the primary winding may be of the order of, let us say, 2000 volts, in which case there will be obtained from the terminals of the secondary winding a voltage of 6000 volts due to the one-to-three step-up voltage transformation ratio. The iron cores may be made up of a ribbon affair, each one inch wide, so that there are seven cores per tubular conductor. If, however, as described above, one end of the primary is grounded and the proper terminal of the secondary connected to the ungrounded end of the primary, there will be obtained a voltage of 8000 volts between ground and the other or high potential terminal of the secondary.

The output voltage obtained from the second- .ary winding terminals may be applied to an electron discharge device, such as a magnetron in order to obtain therefrom very short duration pulses (of the order of microseconds) of high frequency energy in response to similar duration pulses applied to the primary winding of the transformer.

Fig. 2 shows a system employing a plurality of transformers generally of the type shown in Fig. 1, in cascade arrangement, in order to obtain additional step-up voltage transformation ratios.

In Fig. 2, I I0 represents one step-up transformer and Ill represents another step-up transformer.

,. It should be noted that the output of transformer I I0, represented by lead H5, is applied to the primary winding of step-up transformer III to obtain an over-all output in lead H6 of a greatly magnified voltage. The voltage figures shown in Fig: 2 are given merely by way of illusfrom, the dimension of each tubular conductor measured along the length of the element which it surrounds being considerably greater than the transverse dimension of the tubular conductor, and cores of good magnetic qualities individual to and surrounding each of said tubular conductors.

3. A voltage step-up transformer comprising a primary in the form of a plurality of tubular conductors physically spaced from one another, direct connections between the ends of said tubular conductors, whereby said tubular conductors are electrically in parallel relation, and a secondary in the form of an uncoiled conductor insulatingly extending through the interiors of said tubular conductors in series, the dimension of each tubular conductor measured along the length of the secondary which it surrounds being considerably greater than the transverse dimension of the tubular conductor, and iron cores individual to and surrounding each of said tubular conductors over substantially the entire lengths thereof.

4. A voltage step-up transformer comprising a primary in the form of a plurality of tubular conductors physically spaced from one another, direct connections between the correspondingly located ends of said tubular conductors, a connection to ground from one of said ends, a secondary in the form of a conductor insulatingly extending through the interiors of said tubular conductors in series, whereby the voltages induced in said secondary additively combine, cores of good magnetic qualities individual to and surrounding each of said tubular conductors, and 'a connection from that terminal of the secondary which is adjacent the grounded end of the first of said tubular conductors to the end of the last tubular conductor adjacent the other terminal of said secondary.

5. A pairof transformers as defined in claim 4, in cascade relation, there being a direct connection betwen the last terminal of said secondary l. A voltage step-up transformer comprising a primary in the form of a plurality of tubular conductors physically spaced from each other and electrically connected together in parallel electrical relationship, and a secondary in the form of an uncoiled continuous conductor extending through the interiors of all of said tubular conductors, the dimension of each tubular conductor measured along the length of the secondary which it surrounds being considerably greater than the transverse dimension of the tubular conductor, said secondary conductor being insulated from said tubular conductors, and cores of good magnetic qualities individually surrounding said tubular conductors.

2. A voltage transformation transformer comprising a .primary elementand a secondary element magnetically coupled together, one of said elements being constituted by a plurality of tubular conductors physically spaced from one another and connected in parallel electrical relationship, the otherelementcomprising anuncoiled conductor serially looped through the interiors of said tubular conductors but insulated thereof one transformer and those ends of the primary of the next transformer which are not directly connected to ground.

6. A voltage transformer comprising a winding in the form of a cylindrical tubular conductor, another winding in the form of a conductor passing through the interior of said first winding, insulation between said windings, a core of magnetic material surrounding said tubular conductor, a direct current connection to ground from one end of said tubular conductor, and

. a connection from that terminal of said inner conductor which is adjacent the grounded end of said tubular conductor to the other end of said tubular conductor.

7. A voltage transformer comprising a circuit in the form of a plurality of tubular conductors, means connecting said tubular conductors together in electrically parallel relationship, another circuit in the form of an uncoiled conductor insulatingly extending through the interior of each said tubular conductors and leads connecting said uncoiled conductors in series, the dimension of each tubular conductor measured along the length of the uncoiled conductor which it surrounds being considerably greater than the transverse dimension of the tubular conductor, cores of magnetic material surrounding said tubular conductors, and separate terminals for said circuits.

NILS E. LINDENBLAD.

(References on following page) s asmso 5 REFERENKBES @ITED Number The following references are ufrecord in the 1344591 file of this patent: UNITED STATES PATENTS {a 2:181:85 Number Name Date 2,318,095 534,302 Lamp 5., Feb. 26, 1895 2,348,325 L IQELEQB n Mania 1923 2,388, 73

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